EPA'S ENVIRONMENTAL IMAGE 
ANALYSIS SYSTEM 
Dennis B. Crook 
The Bionetics Corporation/EPIC 
Gordon Howard, Jr. 
EMSL-LV, Environmental Photographic Interpretation Center 
P.0. Box 1575 
Vint Hill Farms Station 
Warrenton, Virginia 22186 
ABSTRACT 
The Environmental Protection Agency has developed a computerized system 
to enhance automation of the normal imagery interpretation functions. 
This system, the Image Analysis System (IAS), allows interpreters to 
translate information directly from imagery on a light table into 
real-world coordinates with linear and areal measurements. The IAS 
integrates a standard interactive graphics system with Calma's CGI 
software. Interfaced with this system is a work station containing a 
Richards Mim-1540 light table modified with a digitizing grid. Data are 
extracted directly from the imagery and input through either the 
digitizer or an alphanumeric keyboard on the operator console. This 
console has a graphics CRT terminal to display data and an alphanumeric 
screen to verify coordinates and control mnemonics. The data are 
processed through a minicomputer, compared with a previously entered map 
base, and converted to geographic or UTM coordinates. The operator 
console facilitates comprehensive editing and updating, and data may be 
stored on magnetic tapes after hard copy plots are made. The present 
two-station system may be expanded to a maximum of five stations. These 
features make the IAS an extremely useful, cost-efficient imagery 
analysis device. 
The Environmental Photographic Interpretation Center (EPIC) developed 
the Image Analysis System (IAS) to give the environmental imagery 
analyst a tool to aid in the interpretation of conventional aerial 
imagery. EPIC studied previous attempts to automate photo 
interpretation and concluded that the IAS should aid the interpreter, 
not replace him. 
The main objective of the IAS was to permit photo analysts to extract 
information from an aerial image of non-uniform scale, convert this 
information into geographic or Universal Transverse Mercator (UTM) grid 
coordinates, and provide a camera-ready deliverable product. Storing, 
retrieving, updating, and editing capabilities were also necessary. 
EPA was aware of many recent advances in computer-aided mapping 
procedures. An engineering feasibility study was conducted to determine 
whether a largely turnkey system would increase analysts' productivity 
by eliminating many traditional bottlenecks. Not only was such a system 
deemed feasible, but also the hardware and software were available 
commercially.